Method for wire-wrapping pipe



Dec. 2, 1969 R H, CULLEN ETAL 4 3,481,549

METHOD FOR wIRE-wRAPPING PIPE Filed Nov. '7, 1966 4 Sheets-Sheet l f HEiwf? Zw@ Iw HA 15g/f f@ @ma y/ fr; /Av

W W f-" W f" f-" f-` r v og H. Ca//ew v War/9J f//lolf INVENTORJ BY (ffnud A TTORNE YS Dec. 2, 1969 R H, CULLEN ETAL 3,481,549

METHOD FOR WIRE-WRAPPING PIPE 4 Sheets-Sheet 2 INVENTORS #agde/n nlm/@Filed Nov. '7, 1966 T T ORNEYS v Dec. 2, 1969 R. H. cULLl-:N ETAL3,481,549

METHOD FOR WIRE-WRAPPING PIPE Filed NOV, 7. 1966 4 Sheets-Sheet 3 BY#agdewf ganci A T T ORNE YS Dec. 2, 1969 R, H. cuLLl-:N ETAL 3,481,549

METHOD FOR WIRE-WRAPPING PIPE 4 Sheets-Sheet 4 Filed Nov. 7, 1966 /l T TORNE YS United States Patent C) 3,481,549 METHOD FOR WIRE-WRAPPING PIPERoy H. Cullen and Charles H. Elliott, Houston, Tex.,

assignors, by direct and mesne assignments, to The Youngstown Sheet andTube Company, a corporation of Ohio Filed Nov. 7, 1966, Ser. No. 592,410Int. Cl. B65h 81/04 U.S. Cl. 242-7.02 2 Claims ABSTRACT F THE DISCLOSUREAn elongated member is wrapped with a plurality of wires in a planetarylay by; disposing a series of wires of a predetermined lengthsubstantially along the member, attaching one end of the wires to themember, attaching the opposite end of the wires to a tensioning devicefor maintaining constant tension in the wires during wrapping, and thenrelatively rotating the wires and member. To obtain the planetary lay ofthe wires, said opposite wire ends are held in a manner to permit themto turn about their own axes during wrapping, or alternatively they areheld from such turning after a predetermined degree of twist is appliedto the wires.

This -invention relates to new and useful methods for wire-wrappingpipe, and particularly for helically wrapping armor wire on flexiblepipe.

In the manufacture of ilexible pipe of the type disclosed in U.S. PatentNo. 3,004,779, and other elongate members, it is often necessary ordesirable to wrap one or more layers of wire around the pipe or otherelongate member. Heretofore, such wrapping was accomplished with eithera planetary lay or a taping lay, or modified forms thereof. When wiresare wrapped on a exible pipe with a taping lay, the wires tend to springaway from the core of the pipe or elongate member which is especiallybad when the armored or wire-wrapped pipe is run through a series ofgrippers of the type disclosed in U.S. Patent No. 2,892,535 since anylooseness of the wires is forced to collect at the end of the pipe, orsection thereof, which results in damage to the wires when they aresqueezed by the grippers.

When wires are wrapped with the planetary lay, they tend to hug the coreof the pipe or tubular member instead of springing away, but to producethe planetary lay by previously known apparatus and methods results infurther problems. For example, the prior art employed a separate spindlefor each wire together with special mechanisms to keep the aXes of thespindles parallel to a given plane as the spindles rotate relative tothe base or core being wrapped with the wires from the spindles.

Although it might be thought that such prior art apl paratus could besimplified by rotating the hose or core` relative to stationary spindlesfor the armoring wire, such reversal of procedure does not produce thedesired planetary lay, but instead it produces the undesirable tapinglay.

The present invention relates to methods which solve the problems of theprior art by obtaining the desired planetary lay using eitherpre-twisted wires applied with a taping lay motion from reels or using aplurality of wires which are mounted without reels and are applied byrotating the hose or core relative to the wires. In the latter case, oneend of each of the wires is secured to the hose or core and the wiresare wrapped thereon with the unsecured ends of the wires turning orbeing turned. Alternatively, the wires may be pre-twisted and theunsecured ends of the wires may be held to prevent them from turningduring the wrapping operation. The resulting ice product is awire-wrapped hose or core wherein the wires hug or tightly grip the hoseor core.

It is therefore an object of the present invention to provide new andimproved methods for wire-wrapping iiexible pipe or other elongatemember wherein the wires are wrapped so as t-o hug the core of such pipeor elongate member as with the planetary lay but without thedisadvantages of the prior planetary lay methods and apparatus.

An important object of this invention is to provide a new and improvedmethod of wrapping wires on a core wherein the wires and pre-twisted insuch a direction that when the wires are wrapped with a taping laymotion they will nevertheless lay on the core in a final position whichis the same as that which the wires would have if applied with aplanetary lay motion.

Another object of this invention is to provide a new and improved methodof wrapping wires on a core wherein a plurality of wires may by wrappedfrom a single spindle or support with a taping head motion while layingthe wires in a planetary lay, whereby the wires closely hug the core butare applied without the drawbacks of the conventional planetary laymethod.

A further object of this invention is to provide a new and improvedmethod of wrapping wires on a core wherein one end of each of aplurality of wires is secured to the core and the other ends are notsecured thereto so that upon a rotation of the core, the wires arewrapped thereon while the unsecured ends of the wires untwist, or aredriven to positively untwist same, to thereby obtain a planetary lay ofthe wires on the core.

The preferred embodiment of this invention will be describedhereinafter, together with other features thereof, and additionalobjects will become evident from such description.

The invention will be more readily understood from a reading of thefollowing specification and by reference to the accompanying drawingsforming a part thereof, wherein an example of the invention is shown,and wherein:

FIG. l is an elevation illustrating a wire wrapped on a tube or rod witha typical prior art taping lay;

FIGS. 1A through 1E are sectional views taken on lines 1A-1A through1E1E of FIG. l t-o indicate the rotational movement of the wires asapplied to the elongate member using the prior art taping lay motion;

FIGS. 2A through 2E are views corresponding to FIGS. 1A though 1E,respectively, but illustrating the prior art planetary lay;

FIG. 3 is an elevation illustrating the method and one form of theapparatus of the present invention wherein the individual wires arepre-twisted so that a plurality of wires are applied with a commonspindle using the taping lay motion and obtaining a planetary lay wrap;

FIG. 4 is a schematic view illustrating the present invention;

FIG. 4A is a schematic view wherein the upper row indicates thecondition of the pre-twisted wire and the lower row indicates thecondition of the wire after it has been wrapped on the pipe or otherelongate member;

FIG. 5 is a plan view of one type of tensioning spindle which may beused in carrying out the method of this invention for maintaining atension on the ends of the wires during the wrapping thereof on a pipeor other elongated member;

FIG. 6 is a sectional view taken on line 6-6 of FIG. 5 and furtherillustrates the tension spindle of FIG. 5;

FIG. 7 is a sectional view taken on line 7 7 of FIG. 6 to furtherillustrate the construction of the tension spindle of FIG. 5;

FIG. 8 is a view, partly in elevation and partly in section,illustrating a simplified apparatus for use in carrying out the methodof this invention.

FIG. 9 is a schematic view illustrating the application of a pluralityof wires on a pipe or tube by rotating the pipe or tube over pre-twistedwires;

FIG. 10 is a further illustration illustrating two different types ofapparatus which may be used for applying the wires to the tube orelongate member in accordance with the present invention; and

FIG, l1 is a schematic view of an apparatus for performing the method ofthis invention wherin wires are wrapped on the core by rotating the corerelative to the wires while the free ends of the wires untwist to obtaina planetary lay.

Briey, the present invention relates to a method for applying wire in ahelical wrap on pipe or other elongate members. The term wire as usedherein includes not only the conventional steel and other metal wires,but also include any similar type of element. Preferably, the pipe whichis wrapped with the wire in the present invention is of the typedisclosed in United States Patent No. 3,004,779, but the invention isnot limited thereto.

To provide a background for an understanding of the present invention,the prior art has been illustrated in FIG. 1, FIGS. 1A through 1E andFIGS. 2A through 2E. In FIG. 1, a wire W is illustrated as beingdisposed in a helical wrap on a pipe, rod or other elongate member P.Sectional views taken on lines 1A-1A through 1E-1E of FIG. l have beenprovided to illustrate the pure taping lay of the prior art, using thesmall arrows as shown in FIGS. lA-lE for such purpose. Thus, a singlepitch of the wire W extends from 1A to 1E of FIG. 1. When the wire W islayed on the pipe or other elongate member P with the pure taping lay ofthe prior art, the 'wire W is Iactually rotated about its longitudinalaxis 360 degrees from the point 1A to the point `1E of FIG. l. Therotation is illustrated by the arrows in FIGS- 1A through 1E. Suchrotation of the wire W with the taping lay results in a wire which tendsto spring away from the pipe P and become loose in use. Suchconstruction is particularly detrimental if the `wire W is wrapped witha plurality of parallel wires to form Van armor on a exible hose core orexible pipe of the type disclosed in said United States Patent No.3,004,779. For example, if such looseness develops in the wires, thelooseness will be forced to collect and accumulate when such wires arepassed through gripping devices of the type disclosed in U.S. Patent No.2,892,535. When the loose wires thus collected or accumulated aregripped or squeezed, they Iwill be damaged, sometimes to the point offracture.

The pure planetary lay of the prior art is illustrated in FIGS. 2Athrough 2E and it is assumed that such positions correspond with the cutlines 1A-1A through 1E- 1E, respectively of FIG. 1. With the planetarylay, the

wire W is held during the laying operation so that it does not rotatewith respect to the pipe or other elongate object, as indicated by thesmall arrows in FIGS. .2A-2E. By reason of the planetary lay wrap, thewire W tends to hug and t closely to the external surface of the pipe Por other elongate object which prevents it from becoming loose duringoperation. However, the planetary lay has a number of drawbacks ordisadvantages as explained heretofore.

With the present invention, one embodiment of 'which is illustrated inFIG. 3, a plurality of Wires W are wrapped on a pipe or other elongatemember P from a common spindle S with a taping head motion whileobtaining the planetary lay wrap. Thus, as will be more evidenthereinafter, the method of the present invention has all of theadvantages of both the taping lay technique and the planetary laytechnique of the prior art, Iwhile eliminating the disadvantages ofsame.

To understand how the results of the present invention are accomplished,reference is made to FIGS. 4 and 4A. As illustrated in FIG. 4, theletter P indicates a pipe, rod

or other elongate member, or the core of a ilexible pipe or hose of thetype shown in said Patent No. 3,004,779. A single wire W is shown, witha portion L extended therefrom prior to wrapping on the pipe or elongatemember P, and with another portion L already wrapped on the pipe orelongate member P. It is assumed that one end such as indicated at 10 ofthe wire W is secured either permanently or temporarily to the pipe orelongate member P. Normally, the end 10 of the wire W is secured at acoupling (not shown) for the core of the flexible pipe P.

The letter D in FIG. 4 designates the pitch or one helical revolution ofthe wire W with respect to the pipe P. Such pitch D extends from a toe'. The physical length of the wire W is indicated by L for the unit ofpitch D and therefore the length of the wire L may be referred to as aunit length of the wire W. The extended portion of the wire W may be ofany length and for purpose of illustration is indicated as having a unitlength L which is equal to the unit length L. There may of course be anumber of such unit lengths, each of which is ultimately wrapped or laidhelically on the pipe or other elongate member P.

In accordance with one embodiment of the present invention, each unitlength L is pre-twisted so as to compensate for the rotation or twistingwhich would otherwise occur Iwhen using the prior art taping lay motion.In FIG. 4, various points along the unit length L of the wire W havebeen marked with the letters a, b, c, d, and e, and correspondingpositions of rotation of such unit length of the wire are indicated inthe top row of FIG. 4A, with the short arrows indicating the directionof twist at the particular poinnt marked by such letters a through e,respectively. Thus, if the unit length L is viewed from the left-handend at a and looking towards e, the pre-twisting of such unit length Ais for a full 360 degrees and in a clockwise direction. The unit lengthL is wrapped on the core, pipe or other elongate member P by the tapinglay motion which involves a rotation of core P relative to the wire W,or vice versa, to produce the helical wrap indicated at L' in FIG. 4.During such relative rotation, the free or unsecured end of the wire W,such as the end a (FIG. 4), is held to prevent turning or twisting,whereby the pre-twisting is relieved as the wrapping progresses toobtain the planetary lay wrap as indicated by the arrows in the lowerrow of FIG. 4A. The relative motion between the core P and the wire W isalso schematically illustrated in FIG. 3 of the drawings by the arrowsand dotted lines in connection with the spindle S. It will be seen fromFIG. 3 that the ends of the wires W on the spindle S correspond to thefree or unsecured end a of the wire W in FIG. 4, in that such ends onthe spindle S are likewise prevented from untwisting except to theextent such untwisting occurs during wrapping to produce the planetarylay.

For purposes of explanation, it is assumed that the unit length L wasinitially pre-twisted in the same manner as the unit length L and thenwas wrapped with the taping lay motion, using a spindle S or othersuitable means. The resulting condition of the unit length L' isillustrated in the lower row of FIG. 4A with a', b', c', d', and e'indicating the direction of twist of the wire at each of those points somarked in FIGS. 4 and 4A. The small arrows in the bottom row of FIG. 4Athus illustrate that the wire W is actually laid in its linal wrap withthe wire in the same condition as if it had been laid by the planetarylay motion, as can be seen by comparing the arrows in the bottom row ofFIG. 4A with the arrows for the wire W in FIGS. 2A-2E.

When a plurality of wires W are wrapped simultaneously from a commonspindle S using the taping lay motion indicated in FIG. 3, each of thewires W is pre-twisted in the same manner as described in connectionwith FIG. 4 above so that each of such wires W is nally wrapped or laidinto position on the pipe or other elongate member P as if it had beenlaid by the planetary lay motion.

Thus, all of the wires W are readily applied with the relatively simpleapparatus and the operation of the taping lay motion and apparatus, butthe wires W actually hug and fit closely on the external surface of thepipe P or other elongate member instead of being loosely mounted thereonas would occur with the normal taping lay motion.

In some instances, it may be desirable to over-twist the wire prior toapplying same using the present method, in which case an increasedhugging or tendency to remain in close contact with the external surfaceof the pipe or other elongate member P will be produced. Such additionalpre-twisting may be effected to the extent of the elastic limit of thewire, since such elastic limit of the wire cannot be exceeded intorsion. It will be understood that only three wires W are illustratedin FIG. 3 for simplicity of illustration, but the number of Wires may beincreased or decreased as desired, preferably applying all of the wiresfor each layer of armor on the hose or other :flexible member P in asingle operation.

Various types of apparatus may be employed in carrying out the method ofthis invention. For example, a modified S-1 is illustrated in FIGS. 5-7for three of the wires W, it being understood that the spindle S-1 maybe enlarged to accommodate more wires W if so desired The spindle S-1has a central shaft 15 which is fixed and which is connected to afriction slip disk -16 with a key 17 or other suitable connector. Thefriction slip disk has friction shoes made of rubber, asbestos orsimilar brake type material indicated at 20 for engaging with theinternal surface of a spindle ring 22. A spindle ring 22 is provided foreach of the wires W as best seen in FIG. 7 so that tension may bemaintained on each of the wires W independently of the others. The WiresW are confined between side plates 25 which are secured to the fixedshaft by keys or other suitable connecting means. Friction shoes areurged outwardly by springs Z1 to assure frictional contact of the shoes2.0 with the inner surface of the ring 22 even when wear occurs.

A simplified form of apparatus for carrying out the method of thisinvention is illustrated in FIG. 8, wherein a section of flexible pipeP`1 of the type illustrated in said Patent 3,004,779 is shown. Such pipeP-l is illustrated in FIG. 8 prior to the application of the armor Wirelayers, which are applied with the method of this invention to the coreof such flexible pipe P1. One end of the Wire W is indicated at 30' onthe lefthand end coupling 35 of the flexible pipe P-l. Such end 30- issecured by any suitable means such as a tightly wrapped wire or clamp36. The Wire W is pre-twisted in the same manner as explained inconnection with FIGS. 4 and 4A, such pre-twist being maintained by africtional lock or key schematically shown at 40 in FIG. 8 within a tube41. The tube 41 is shown as disposed on a support 42 which has afeed-off guide 43 for the pipe P-1. A sleeve forming a post armor guide45 supports the flexible pipe P-1 at the left-hand end of FIG. 8 and itin turn is mounted on a base or support 46. A guide rod or bar 50 isdisposed within the guide sleeve 45 and one end thereof is temporarilythreaded or otherwise connected to the coupling 35. Such rod `50 has ahelical groove 51 formed therein which has the helical configurationdesired for the Wrapping of the wire W on the pipe P-1. A

pawl 52 is formed internally of the sleeve 4S and extends into thegroove 51. Suitable -means (not shown) is provided for moving the rod`50 longitudinally to the left as viewed in FIG. 8 and as indicated bythe arrow so as to cause the rod 50 to rotate during such longitudinalmovement as the pawl 50 follows the groove 51. As the rod 50 is thusmoved in a helical path, the pipe P-1 is moved in the same helicalmotion and the wire W is pulled from the tube 41 while being maintainedunder tension by the friction lock 40 so as to Wrap the wire W in thehelical wrap corresponding to the helical groove 51. Since the wire W ispre-twisted, it assumes a final condition corresponding to the planetarylay illustrated by the bottom row of FIG. 4A as previously explained.

It will be understood that a plurality of the wires W may be wrapped ina single operation to fully armor each layer of wires on the core of thepipe P-1 at one time if so desired. When the full length of the wire Whas been wrapped on the length of the pipe P-l, the end of the wire W issevered and is secured to the other end coupling 37, using the methodsfor effecting such coupling disclosed in the prior art.

In FIG. 9 of the drawings, a further modification of the method of thisinvention is illustrated. The illustration of FIG. 9 includes a pipe Por other elongate member with a plurality of Wires W which have beenpretwisted in the manner explained above in connection with FIG. 4. SuchWires W are secured in parallel relationship, the number of which mayvary. The wires W may be laid out on a plane such as a fioor, one end ofthe pipe P may be secured to one end of the plurality of parallel wiresW, such ends being designated at 60 in FIG. 9, and then the pipe P maybe rolled along the floor to roll the parallel wires W onto the pipe P.Alternatively, and as specifically illustrated in FIG. 9, the ends 60may be initially attached or temporarily secured to the pipe P at thedesired point, the pipe P may be fixed in a location for rotation with abackup plate 61 having an opening 61a through which the plurality ofwires W extend. As the pipe P is rotated, the wires W are pulled ontothe rotating pipe or tube T to thus cover such pipe or tube P with thewires W. The number of wires are illustrated in FIG. 9 as being threefor simplicity, but the number may be increased or decreased aspreviously explained, using the same procedure.

In FIG. 10, the Pipe P-1 preferably corresponds with the core of thepipe illustrated in Patent No. 3,004,779. The pipe P-1 may be rotatedand advanced longitudinally to the right as viewed in FIG. l0 with thespindle S for the wires W in a fixed position. Alternatively, the pipeP-l may be fixed and the spindle rotated as explained in connection withFIG. 3 of the drawings.

Also, in FIIG. 10 another procedure is illustrated wherein a yoke Y isillustrated for the ends of the Wires W-1. Such yoke Y is connected tothe ends of the Wires which have been pre-twisted so that a-s the pipeP-1 is rotated, the Wires W-1 are wrapped as illustrated so as to obtainthe same results and condition heretofore explained in connection withFIG. 4.

In FIG. l1, still another embodiment of the present invention isillustrated, wherein wires are `applied to the hose core without the useof reels and normally without any pre-twisting of the Wires. One type ofapparatus which may be used for carrying out such method isschematically illustrated in FIG. 11. Thus, as illustrated in FIG. 11, apredetermined length of hose P-Z which is to be Wrapped by a pluralityof armor wires such as wires W-Z are mounted on the apparatus for thewrapping operation. The hose core P-2 is threaded at one end to arotatable mandrel 70 and it is -secured at its other end to a guidemandrel or pilot 71. The mandrel 70 is rotated by any suitable drivemeans such as an electric motor 72 which drives through a gear box 73and sprockets or gears 74 and 75, to which are connected a pulley orchain 76. The wire W-Z illustrated in FIG. l1 is merely representativeof a plurality of wires which are disposed through the openings 77a in aWire guide plate 77. Each of the wires W-Z passes through the opening77a and through a space between the jaws of a closing die -80 which isdisposed around the hose core P-2. The ends of the wires W-Z adjacentthe mandrel 70 are secured to the hose core P-2 by a holding nut 81 orsimilar retaining device. At the start of the wrapping operation, theclosing die 80 is disposed adjacent the nut 81 and all of the wires W-Zare extended substantially longitudinally and parallel with the axis ofthe hose P-Z, but spaced outwardly therefrom so as to completelysurround such hose core P-Z. The closing dies 80, the comb 7S and thewire guide plate 77 are all preferably mounted together on a frame 82which has rollers 83 so that such components move as a unitlongitudinally on a track or frame support indicated by the rails 84. Itis to 'be noted that the comb 78 is connected to the wire guide plate 77by a connector tube 85 through which the core P-Z initially extends. Theframework 82 is operably moved longitudinally by any suitable means soas to move the wheels or rollers S3 on the track 84 to the right as viewin FIG. ll when wrapping the wires W-Z Von the hose core P-Z. Asillustrated in FIG. l1, such operating means includes an endless chain87 on each side of the frame 82, each of which is driven by the motor 72through a gear box 88, shafts 88a and sprockets 88h engaging the endlesschains 87. The direction of rotation of the sprockets 88b determines thedirection in which the closing dies 80 and the wire guide plate 77 aremoved longitudinally With respect to the hose core P-2, as Will be moreevident hereinafter.

The guide mandrel or pilot 71 is supported on any suitable support suchas support rollers 90 which are mounted on a retractable base 91.

The unsecured or free end of each of the wires W-Z is attached to aswivel 93 which is resiliently connected to a carriage plate 94 by aspring 95. The carriage plate 94 is mounted in any suitable means forlimited longitudinal travel to compensate for the movement of the endsof the wire W-2 during the wrapping operation, as will be explained.Thus, the carriage plate 94 is mounted on a stem 94a which has a pistondisposed inwardly of a cylinder 95 so that hydraulic fluid provides acushion to limit the amount of the movement of the ends of the wireconnected to the swivel 93, while allowing enough movement to permit thewrapping of the wires W-Z helically on the core P-2. The cylinder 95 isconnected to a suitable frame or support that is indicated at 96.

In carrying out the methods as illustrated in FIG. 1l, the plurality ofwires W-2 are secured to the hose core P-2 at the mandrel end with a nut81 and with the closing dies 80 over the wires W-Z adjacent such nut 81.Each of the wires W-2 extends through one of the openings 77a in theguide plate 77 and through the spaces between the teeth of the comb 78.Also, each of the wires W-Z is maintained under tension and is connectedwith a swivel 93 or other suitable means for allowing the wire W-Z toturn or untwist during the wrapping operation. Also, instead of simplyallowing the ends of the wire to turn at the swivels 93, each of thewires W-Z may be forced to untwist or rotate about its own longitudinalaxis during the wrapping operation to obtain the close-tting planetarylay of such wires on the core P-2.

When it is desired to begin the wrapping, the mandrel 70 is rotated andthe endless chains 87 are actuated to move the closing die 80 togetherwith the guide plate 77 and the comb 78 longitudinally away from themandrel 70. Since the wrapping of each of the wires W-Z on the hose coreP-2 occurs helically, it requires a greater length of the wires W-Z thanthe actual length of the hose core P-2. For this reason, the ends 93 ofthe wires W-2 tend to move towards the forward end of the hose core P-2during the wrapping operation and such movement is permitted by thetravel of the piston on the piston stem 94a within the cylinder 95,maintaining tension on the wires W-2 at all times. The pilot 71 entersthe opening 9417 and actually moves within the bore of the stem 94aduring the travel of the equipment longitudinally during the wrappingoperation. The rollers 90 may be moved downwardly out of the way of theguide plate 77 by any suitable mechanism so that the predeterminedlength of the hose core P-Z may be wrapped by continuous movement in onedirection of the guide plate '77 and the closing dies with respect tothe hose core P-Z.

The method thus described with respect to FIG. 1l produces a wrap whichhas the Wires W-2 disposed thereon with the planetary lay as illustratedin the bottoni row of FIG. 4A.

The foregoing disclosure and description of the invention isillustrative and explanatory thereof and various changes in the size,shape and materials, as well as in the details of the illustratedconstruction may be made within the scope of the appended claims withoutdeparting from the spirit of the invention.

What is claimed is:

1. A method of wrapping wires on an elongate member, comprising thesteps of,

securing one end of each of a plurality of wires in proximity to one endof an elongate member, positioning the wires substantiallylongitudinally with respect to the elongate member, applying tensiondirectly to approximately the other end of each wire which permittingthe other end of each wire to turn about its longitudinal axis,

rotating the elongate member and helically wrapping the wires on theelongate member,

maintaining said wires in substantially their original orientation abouttheir own axes while they are being wrapped about the elongate member,

said wires acting as drive shafts to rotate their other ends while beingwrapped,

and moving the other ends of the wires along their own axes toward saidsecured ends during said wrapping step while continuing to apply saidtension.

2. A method of wrapping wires on an elongate member comprising the stepsof,

securing one end of each of a plurality of wires in proximity to one endof an elongate member, positioning the wires substantiallylongitudinally With respect to the elongate member,

applying tension directly to approximately the other end of each wirewhile permitting the other end of each wire to turn about itslongitudinal axis, relatively rotating the elongate member and wires andhelically wrapping the wires on the elongate member, maintaining saidwires in substantially their original orientation about their own axeswhile they are wrapped about the elongate member, and moving the otherends of the wires along their own axes toward said secured ends duringsaid wrapping step while continuing to apply said tension.

References Cited UNITED STATES PATENTS 2,342,342 2/ 1944 Hotchkiss etal. 57-11 2,347,631 4/ 1944 Hotchkiss 57-11 2,3 60,783 10/1944MacCreadie 57-13 2,967,390 1/1961 McCormick 57-11 3,037,343 6/ 1962 Haaset al. 57-9 BILLY S. TAYLOR, Primary Examiner U.S. Cl. X.R.

